Where should a drip leg be installed in a gas line?

A drip leg should be installed in a vertical line. This is the correct choice because a drip leg serves the purpose of collecting condensate and impurities that may accumulate in a gas line. By placing it vertically, any liquid that forms can drain down into the drip leg, preventing it from traveling further down the gas line where it could cause problems, such as blockages or equipment malfunctions.

Installing the drip leg in a horizontal line would not facilitate proper drainage of any condensate, and the potential for liquid to accumulate in the line could lead to hazardous situations. Positioning it at the meter or the burner could also be ineffective, as these locations may not provide the optimum setting for collecting contaminants and ensuring the gas delivered to appliances is clean and safe. Therefore, the vertical installation is critical for effective functioning of the drip leg in maintaining gas line integrity.